Pathology V Flashcards
What causes secondary hyperparathyroidism?
Secondary hyperplasia due to decreased gut calcium absorption and increased phosphate. Most often occurs in chronic renal disease (hypovitaminosis D which decreases calcium absorption) (p.300)
What lab findings are consistent with a diagnosis of secondary hyperparathyroidism?
Hypocalcemia, hyperphosphatemia in chronic renal failure (hypophosphatemia in most other causes), increased alkaline phosphatase, increased PTH (p.300)
What lab finding distinguishes primary hyperparathyroidism from secondary hyperparathyroidism?
Primary: hypercalcemia; secondary: hypocalcemia (p.300)
What lab finding distinguishes secondary hyperparathyroidism due to chronic renal failure from secondary hyperparathyroidism due to other causes?
In chronic renal failure- hyperphosphatemia, in other causes- hypophosphatemia (p.300)
What is renal osteodystrophy?
Bone lesions due to secondary or teritary hyperparathyroidism caused by renal disease (p.300)
What causes tertiary hyperparathyroidism?
Refractory (autonomous) hyperparathyroidism due to chronic renal disease (p.300)
What lab findings are consistent with a diagnosis of tertiary hyperparathyroidism?
Highly elevated PTH, elevated calcium (p.300)
What are the three most common causes of hypoparathyroidism?
Accidental surgical excision, autoimmune destruction, DiGeorge syndrome (p.300)
What findings are consistent with hypoparathyroidism?
Hypocalcemia, tetany (p.300)
What is Chvostek’s sign?
Contraction of the facial muscles due to tapping of the facial nerve; caused by hypoparathyroidism and hypocalcemia (p.300)
What is Trosseau’s sign?
Carpal spasm due to occlusion of the brachial artery with BP cuff; caused by hypoparathyroidism and hypocalcemia (p.300)
In what conditions are Chvostek’s sign and Trosseau’s sign seen?
Hypoparathyroidism and hypocalcemia (p.300)
What is pseudohypoparathyroidism?
A genetic condition causing kidney unresponsiveness to PTH (p.300)
What is another name for pseudohypoparathyroidism?
Albright’s hereditary osteodystrophy (p.300)
How is Albright’s hereditary osteodystrophy inherited?
Autosomal dominant inheritance (p.300)
What findings are associated with pseudohypoparathyroidism (Albright’s herediary osteodystrophy)?
Hypocalcemia, shortened 4th/5th digits, short stature (p.300)
Name two common causes of PTH independent hypercalcemia?
Excess calcium ingestion, cancer (p.300)
What is the most common form of pituitary adenoma?
Prolactinoma (p.301)
What are the clincial findings associated with pituitary adenoma?
In prolactinoma- amenorrhea, galactorrhea, low libido, infertility (p.301)
What hormone is low in cases of pituitary adenoma?
Decreased GnRH (p.301)
What types of visual changes may be seen in a patient with pituitary adenoma?
Bitemporal hemianopia due to impingement of optic chiasm (p.301)
What is the pharmalogical treatment for pituitary adenoma (prolactinoma)?
Dopamine agonists- bromocriptine or cabergoline. This can cause shrinkage of prolactinomas (p.301)
What causes acromeagly?
Excess GH in adults, usually caused by pituitary adenoma (p.301)
What is the difference between excess GH in adults vs children?
In children, increased linear bone growth causes gigantism (p.301)
What are the clinical findings in a patient with acromeagly?
Large tongue with deep furrows, deep voice, large hands and feet, coarse facial features, impaired glucose tolerance (insulin resistance) (p.301)
What lab finding is consistent with a diagnosis of acromeagly?
Increased serum IGF-1 (p.301)
